UUJUCUVCS 0 to be able to determine the equivalent resistance of resistors connected in series 0 to be able to determine the equivalent resistance of resistors connected in parallel 0 to be able to determine the equivalent resistance of a network of resistors 0 to be able to predict and test the current through and voltage across various elements in more complex circuits 0 to understand that not all resistors are linear resistors Overview: In this lab, you will learn how to determine the equivalent resistance of resistors in series, in parallel and in more complex configurations through both calculation and measurement. You will also learn that not all resistors are linear. Equipment: 1 digital multimeter various linear resistors (22!), 399, 519, 7552) alligator clip leads 2 1.5V batteries Investigation 1 Equivalent resistance of resistors connected in series and parallel Investigation 1.1 Resistors in series a. Measure the resistance of three different resistors and record the values below. R1 = _ R2 = R3 = b. Connect two of the resistors in series. Measure the resistance across both resistors. Record the resistance below. This is the equivalent resistance of the two resistors in series. Reg: 75 c. Connect three of the resistors in series. Measure the resistance across the series. Record the resistance below. This is the equivalent resistance of the three resistors in series. Rm: (1. Based on your data, write down an equation for the equivalent resistance when resistors are added in series. Investigation 1.2 Resistors in parallel 8. Using three resistors you used in Investigation 1.1, connect two of the resistors in parallel. Measure the resistance across the parallel conguration. Record the resistance below. This is the equivalent resistance of the two resistors in parallel. Rm: b. Connect all three of the resistors in parallel. Measure the resistance across the parallel conguration. Record the resistance below. This is the equivalent resistance of the three resistors in parallel. Reg: c. Is the equivalent resistance of your measurements in agreement with the equation below? 1_1+1+1 Rea R1 R2 R3 Show your work. 76 d. If all three of the resistors in parallel had the same resistance (and you can try this, if you want to), is the equivalent resistance of the parallel network greater than, less than or equal to the resistance of the individual resistors? Explain. Equipment: 1 digital multimeter _ various linear resistors (2252, 399, 51!), 75(2) alligator clip leads 2 1.5V batteries Investigation 2 Equivalent resistance of more complex networks Consider the network of resistors shown on the next page. By systematically replacing the series and parallel combinations with the equivalent resistance, the whole network could be replaced by a single equivalent resistor. This is demonstrated in the diagram on the next page. The network could be replaced by a single 59 resistor. 77 Make sure you understand this process before you proceed. Ask your TA, if you don't understand. 78 a. Test your understanding by considering the diagram below, CODStI'PCted 0f the resistors you labeled R1, R2, and R3 in Investigation 1 and calculating the equivalent resistance. b. Check your answer by measuring the equivalent resistance. Is your calculation in agreement with your measurement? . 79 Equipment: 1 digital multimeter 4 bulbs 4 519 resistors alligator clip leads 2 1.5V batteries 1 switch Investigation 3 Non-linear resistors and multimeter measurements a. Design a circuit consisting of a battery, a single bulb, and a switch. Include a method of measuring the current through the battery. Draw the circuit in the space below. b. Measure the current through the battery when the switch is closed. Record the value in the space below. Use appropriate units. c. Design a circuit consisting of four bulbs in which the current through the battery 15 approxrmately the same as the current through the battery in a single bulb circuit. Draw your circuit in the space below. (There is more than one possible answer.) 80 g --AAnannnn000